With a 43 MP sensor you get a resolution of about 3000 dpi for the smallest 120 format 60x40, scanned horizontal. That's not enough in my opinion.
A solution could be to scan in two rows and two columns and to stitch the frames. The bigger the format the worse it gets.
As for the Plustek Opticfilm 120, RattyMouse was contemplating buying one (I saw a question about Silverfast Software from him recently). Perhaps he could chime in.
A German web-shop specialized in scanners (ScanDig) is saying that they don't sell the Plustek 120 anymore because there were too many customers with problems.